As for the thread starter, I bought my first bike in 09 and I looked at mostly personal listings. I don't recall seeing as much of those don't waste my time ads as I see these days. Of course, I didn't test ride any bikes at that time because I didn't have the experience nor a license at that point. I bought my first bike without ever having ridden. But I did check it out real well and I got a lot of advice on that particular model. I was going for a cruiser and a lot of people recommended a Honda Shadow 750 or a Yamaha VStar 650(?). I ended up with the Shadow.
Recently, I upgraded to a Harley. I test rode bikes at 2 dealerships and I'm pretty sure I could have test rode at the other 2 places, as well, if I chose to do that. The first place, Gail's Harley Davidson in Grandview made me fill out a form that basically said if I wrecked it, I buy it. The paperwork made it sound like they would require that I followed/rode with someone from their dealership. But when I got out there and asked about that, the salesman said they weren't planning to ride with me unless I wanted them to. Of course I declined and test rode a couple bikes by myself.
The other place, Topeka Harley let me ride without anything other than a copy of my license. Of course, they did know that I had a bike and was looking to sell it or trade it in to them.
I do wonder, however if its up to their discretion as to whether they allow you to test ride solo or whatever.
You can't buy happiness. But you can buy beer. And that's pretty much the same thing.